Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.15.1 (ACE)
18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The solubilization of angiotensin I-converting enzyme (peptidyldipeptide hydrolase, EC 3.4.15.1) from rabbit lung was carried out using trypsin treatment. A good recovery of 76% was obtained. The enzyme from solubilized fraction was purified using colums of Sephadex G-200, hydroxyapatite and DEAE-cellulose. The purified enzyme was shown to convert angiotensin I to angiotensin II and also to inactivate bradykinin. The specific activity of the enzyme was 24.3 units/mg protein for hippurylhistidylleucyl hydroxide and 0.182 mumol/min per mg protein for angiotensin I. The enzymic activity obtained after trypsin treatment for 5 h could be divided into two components: (i) an enzyme of molecular weight 300 000 (peak II) and (ii) an enzyme of molecular weight 145 000 (peak III), by Sephadex G-200 gel filtration. The molecular weight of the denatured enzyme was found to be 155 000 by disc gel electrophoresis in the presence of sodium dodecyl sulfate. Km values of peak II and peak III fraction for Hippuryl-His Leu-OH were 2.6 mM.
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PMID:Solubilization of angiotensin I-coverting enzyme from rabbit lung using trypsin treatment. 18 21

Two independent mutants of Escherichia coli deficient in dipeptidyl carboxypeptidase activity (Dep-) were isolated after mutagenesis with ethyl methanesulfonate. Mating experiments and introduction of specific episomes indicated that the responsible gene was located at approximately 27--31 min on the E. coli chromosome. The Dep- mutants differed from the parental strain in their inability to grow with N-acetylalanylalanylalanine as the sole nitrogen source. Revertants selected for growth on this substrate of the enzyme were found to have reacquired the activity. Enzyme activity was highly sensitive to inhibition by 1-(D-3-mercapto-2-methylpropanoyl)-L-proline (SQ 14225), a potent inhibitor of mammalian dipeptidyl carboxypeptidase (angiotensin-converting enzyme, peptidyl dipeptidase, EC 3.4.15.1). This compound also reduced the rate of growth of the wild type with N-acetylalanylalanylalanine but not with ammonium sulfate. A fraction of the enzyme was released into the medium by osmotic shock, indicating that its presence in the periplasmic space may account for growth with N-acetylated peptides that cannot be taken up by E. coli. In addition to providing information about the specific role of this exopeptidase in E. coli, the Dep- mutants may prove useful for delineating the regulation and cellular function of dipeptidyl carboxypeptidases in higher organisms.
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PMID:Escherichia coli mutants defective in dipeptidyl carboxypeptidase. 21 6

Angiotensin-converting enzyme [ACE (peptidyl-dipeptidase A, EC 3.4.15.1)] was purified from a total cell membrane fraction of rat intestinal mucosa. A 4,500-fold purification was achieved after affinity chromatography with lisinopril-Sepharose and gel filtration. The final preparation was judged to be homogenous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent molecular weight of 160,000. The purified protein is a glycoenzyme containing 12% N-linked carbohydrate. Purified ACE had a specific activity of 65 U/mg protein with benzoyl-Gly-His-Leu as substrate. A kinetic analysis showed that the enzyme had the maximal velocity with substrates containing proline at the COOH-terminal end. Inhibitor studies indicated that the enzyme is a metalloprotein. Along the proximal-distal axis of the small intestine, ACE activity is most predominant in the proximal to middle portions, decreasing toward the distal end. This pattern was also observed for ACE mRNA and protein, suggesting that ACE expression is controlled at the level of mRNA. Perfusion of benzoyl-Gly-His-Leu in vivo through a segment of intestinal jejunum demonstrated that ACE is an important intestinal dipeptidyl carboxypeptidase, participating in the digestion and assimilation of dietary peptides.
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PMID:Rat intestinal angiotensin-converting enzyme: purification, properties, expression, and function. 132 52

An extracellular protease derived from the culture broth of a microorganism, a Streptomyces species, produced Boc-Pro-Pro and diproline from Boc-Pro-Pro-Pro-Pro. The enzyme was purified 726-fold, with a yield of 2.6%, by ammonium sulfate fractionation, ion-exchange chromatography, and gel filtration chromatography. The molecular weight of the enzyme was determined to be 65,000 by gel filtration and 70,000 by SDS-PAGE. The enzyme released a C-terminal dipeptide from peptide substrates having a C-terminal proline and a penultimate proline or alanine residue, but did not hydrolyze angiotensin I or bradykinin. When the enzyme hydrolyzed Leu-Pro-Pro-Pro-Pro-Pro, it produced Leu-Pro-Pro-Pro and Pro-Pro before producing Leu-Pro. The enzyme thus seems to be a kind of dipeptidyl carboxypeptidase, its substrate specificity being very different from that of the well known dipeptidyl carboxypeptidases [EC 3.4.15.1] such as the angiotensin-converting enzyme.
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PMID:Purification and characterization of a novel dipeptidyl carboxypeptidase from a Streptomyces species. 140 Feb 66

Plasmids carrying the Salmonella typhimurium dcp gene were isolated from a pBR328 library of Salmonella chromosomal DNA by screening for complementation of a peptide utilization defect conferred by a dcp mutation. Strains carrying these plasmids overproduced dipeptidyl carboxypeptidase approximately 50-fold. The nucleotide sequence of a 2.8-kb region of one of these plasmids contained an open reading frame coding for a protein of 77,269 Da, in agreement with the 80-kDa size for dipeptidyl carboxypeptidase (determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration). The N-terminal amino acid sequence of dipeptidyl carboxypeptidase purified from an overproducer strain agreed with that predicted by the nucleotide sequence. Northern (RNA) blot data indicated that dcp is not cotranscribed with other genes, and primer extension analysis showed the start of transcription to be 22 bases upstream of the translational start. The amino acid sequence of dcp was not similar to that of a mammalian dipeptidyl carboxypeptidase, angiotensin I-converting enzyme, but showed striking similarities to the amino acid sequence of another S. typhimurium peptidase encoded by the opdA (formerly optA) gene.
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PMID:Cloning and nucleotide sequence of the Salmonella typhimurium dcp gene encoding dipeptidyl carboxypeptidase. 153 4

The membrane-bound form of aminopeptidase P (aminoacylprolyl-peptide hydrolase) (EC 3.4.11.9) was purified to apparent homogeneity from bovine lung microsomes. The enzyme was solubilized using phosphatidylinositol-specific phospholipase C (Bacillus thuringiensis), indicating that bovine lung amino-peptidase P is attached to membranes via a glycosylphosphatidylinositol anchor. The enzyme was purified 1900-fold with a yield of 25% by chromatography on decyl-agarose, omega-aminodecyl-agarose, a second decylagarose column, DEAE-Sephacel, and an ultrafiltration step. Native gradient polyacrylamide gel electrophoresis revealed a single stained protein band whose position in the gel corresponded to cleavage of the Arg1-Pro2 bond of bradykinin. The Mr was 360,000 by gel permeation chromatography and 95,000 by reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The substrate specificity of aminopeptidase P was determined using approximately 50 peptides with proline in the second position. The enzyme could hydrolyze lower NH2-terminal homologs of bradykinin, including Arg-Pro-Pro, which was used as the routine substrate in a rapid fluorescence assay performed in the absence of added Mn2+. Some peptides having NH2-terminal amino acids other than arginine were also cleaved. Aminopeptidase P appeared to favor peptides that had 2 proline residues or proline analogs in positions 2 and 3 of the substrate. In general, tripeptides having a single proline residue in position 2 were poor substrates. Aminopeptidase P was inhibited by a series of peptides, 3-8 residues long, having an NH2-terminal Pro-Pro sequence. The enzyme was also inhibited by metal-chelating agents, 2-mercaptoethanol (4 mM), p-chloromercuribenzenesulfonic acid, and NaCl at concentrations greater than or equal to 0.25 M. The purified enzyme had a pH optimum of 6.5-7.0 and was most stable in the basic pH range. A role for membrane-bound aminopeptidase P in the pulmonary inactivation of circulating bradykinin is proposed.
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PMID:Membrane-bound aminopeptidase P from bovine lung. Its purification, properties, and degradation of bradykinin. 153 67

The molecular forms of angiotensin converting enzyme (ACE; EC 3.4.15.1) in preparations of pig brain cortical microvessels and striatal synaptosomal membranes have been identified by immunoelectrophoretic blot analysis. The cortical microvessels contained only the endothelial form of the enzyme, Mr 180,000, which comigrated with pig kidney ACE on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In contrast, the synaptosomal membranes contained only a smaller form of ACE, Mr 170,000, which represents the neuronal form of the enzyme. No significant differences in inhibitor sensitivity or substrate specificity were detected between the two forms of ACE. In particular, neurokinin A was resistant to hydrolysis by either microvessel or synaptosomal membrane ACE, and the pattern of hydrolysis of substance P by the two preparations was identical.
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PMID:Characterization of neuronal and endothelial forms of angiotensin converting enzyme in pig brain. 164 60

Angiotensin converting enzyme (EC 3.4.15.1) from bovine seminal plasma was shown to exist in two distinct forms. A lower molecular weight form of the enzyme having higher activity was purified to homogeneity. Final recovery of the enzyme was 18.37%. The apparent molecular weight of the enzyme was estimated to be 1.99 x 10(5) by gel filtration. A value of 1.8 x 10(5) was obtained for the reduced and denatured enzyme by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Stokes' radius, diffusion coefficient and intrinsic viscosity were determined to be 51.89 A degree, 4.2 x 10(-7) cm2/sec and 4.42 cc/g, respectively. Chloride ions were required for the enzyme activity. Studies with EDTA suggest that metal ions which are tightly bound, are required for its activity. Enzyme was inhibited by some heavy metal ions and required disulfide linkages at its active site. Trypsin treatment of the urea denatured enzyme produced a catalytically active Mr 32,000 daltons fragment.
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PMID:Purification and characterization of angiotensin converting enzyme-II from bovine seminal plasma. 166 20

We purified angiotensin I-converting enzyme (ACE) from pig and human lung and plasma for comparison of some physicochemical properties between the endothelial membrane-bound form and the soluble form of the enzyme. After affinity chromatography on Sepharose CL-4B/lisinopril, gel-filtration HPLC on Superose 12 achieved homogeneity for both forms as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Whatever the source of ACE, the molecular weight was 300 +/- 40 kDa after calibration of Superose 12 with standard globular proteins and 172 +/- 4 kDa by SDS-PAGE, with or without reduction, a result suggesting interactions between the glycopolypeptide chain and the chromatographic gel possibly related to the overall shape and sugar content of the enzyme. Ion-exchange HPLC analysis on TSK-DEAE showed that the membrane-bound and soluble forms of ACE are not isoenzymes, although isoelectrofocusing did show that the isoelectric point of soluble ACE was lower than those of tissue ACE, suggesting a different glycosylation. No significant difference between porcine and human ACE appeared. HPLC methods seem to be of particular interest for the purification of ACE with a high yield and for the analysis of its putative differently glycosylated isoforms.
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PMID:Purification and analysis of lung and plasma angiotensin I-converting enzyme by high-performance liquid chromatography. 166 73

A rapid and highly efficient procedure for purification of kininase II from human seminal plasma is described. After ultracentrifugation, the enzyme was purified by gel filtration on Sepharose 6B CL and ion exchange chromatography followed by affinity chromatography of EDTA-inhibited enzyme on bradykinin-Sepharose. The enzyme was specifically inhibited by Captopril and BPP9a but not by phosphoamidon. PAGE in the presence of sodium dodecyl sulfate under reducing conditions resulted in two major protein bands with apparent molecular masses of about 55 kDa and 65 kDa and two faint protein bands at higher molecular masses. Antibodies raised against the major protein bands showed full cross reactivity with all four protein bands. The presented data indicate that kininase II of subunits.
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PMID:Proteins of the kallikrein-kinin system in human semen. Isolation and properties of kininase II. 196 11


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